The objective of this research is to study the effects of preschool as a milieu upon the behavior of children. Formal lesson settings are to be analyzed to determine the effects of activity-properties and of teacher behaviors upon the task-involvement, deviancy, and gleefulness of children. Free play settings are to be analyzed for their attraction and holding power, and for their effects upon constructiveness, sociality, joyfulness, conflict, and imitation-modelling behavior. Comparisons between formal lesson settings and free play settings are to be conducted. The data consist of videotapes recordings obtained in an integrated preschool.